<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="vue.js"></script>
</head>
<body>
  <div id="app">
    <my-button>
      aaabbb
    </my-button>
  </div>
</body>

<template id="btn">
  <div>
    <slot></slot>
    <button>加1</button>
    <slot></slot>
  </div>
</template>
<script>
    const Button = {
        template: '#btn'
    }
    const vm = new Vue({
        el: '#app',
        components: {
            'myButton': Button
        }
    })
</script>
</html>